The invention relates to horizontal well drilling and more particularly to a flexible hose assembly for horizontal well drilling.
In the process of drilling for hydrocarbons such as oil and natural gas, vertical wells have been used most often in the past. Those wells will produce for a given amount of time, then begin to dry up. At that point, it is advantageous to drill out horizontally from the vertical well in order to try and increase production of, for example, crude oil.
There have been several attempts to find an economically viable and reliable system for drilling into the untapped pay zones adjacent an existing vertical well. Horizontal drilling has been proposed as an alternative and has been described in U.S. Pat. Nos. 5,853,056, 5,413,184, 5,934,390, 5,553,680, 5,165,491, 5,458,209, 5,210,533, 5,194,859, 5,439,066, 5,148,877, 5,987,385, 5,899,958, 5,892,460, 5,528,566, 4,947,944, 4,646,831, 4,786,874, 5,410,303, 5,318,121, 4,007,797, 5,687,806, 4,640,362, 5,394,951, 1,904,819, 2,521,976 and Re. 35,386, the contents of all of which are incorporated herein by reference.
U.S. Patent No. 5,413,184 describes a method of horizontal drilling which utilizes flexible hose and a high pressure nozzle blaster to bore into the earth""s strata at significant depths, such as 4000 feet. The nozzle uses high pressure water to clear a path through the strata. The nozzle is advanced through the strata by applying weight to the hose, i.e., slacking off the tension in the vertical portion of the hose. Essentially, the weight of the 4000 feet of hose above the nozzle is used to apply pressure to the nozzle, thus forcing it along the horizontal path. While this method is effective at significant depths due to the large amount of weight available, it is less effective at shallower depths. At shallow depths, there simply is not enough weight available to supply sufficient force to advance the nozzle blaster through the strata. Thus, there is a need for an apparatus that will effectively advance a drilling tool such as a nozzle blaster horizontally through the earth""s strata for horizontal drilling at shallow depths.
A flexible hose assembly for horizontal well drilling is provided. The hose assembly comprises a flexible hose and a nozzle blaster attached to the hose. The hose has a plurality of holes disposed therein, each of which is adapted to direct pressurized aqueous liquid in a direction forming an angle less than 80xc2x0 with the longitudinal axis of the hose in an upstream direction from the location of the hole. A method of horizontal well drilling is also provided which includes the steps of: providing a flexible hose assembly having a nozzle blaster at one end of a flexible hose, and at least one thruster coupling with a plurality of holes disposed about its circumference; lowering the hose assembly to a desired depth in a vertical well, and redirecting the hose assembly along a substantially horizontal direction, substantially perpendicular to the longitudinal axis of the vertical well; forcing at lest 2,000 psi aqueous liquid through the hose, the nozzle blaster and the holes in the couplings; and drilling a bore substantially horizontally into the earth""s strata adjacent the vertical well.